Process for treating petroleum oil



June 23, 1931. c. P. DUB-BS PROCESS FOR TREATING PETROLEUM OIL Filed July 3 1922 Patented June 23, 1931 UNITED STATES PATENT OFFICE oARBON P. nunnsor wrLMnr'rn, ILLINOIS, ASSIGNOR ro UNIVERSAL OIL PRODUCTS COMPANY, or crrroaoo, ILLINOIS, A CORPORATION or sourn DAKOTA rnocnss FOR TREATING PETROLEUM I'I.

Application filed July 31, 1922. 'Serial NO. 578,703.

ing point. 'The process is preferably operated continuously and under. a substantial pressure of the generated vapor. Among the salient objects of the invention are to provide a process in which-the oil is heated toa cracking temperature and passed successi'vely through a series of vaporizing chambers which are connected so that the vapor pressures in the successive chambers may be accurately controlled and the liquid Oil passing therethrough may be regulated to recycle the residual products or divert the residual products, as desired. I I

The single figure is a diagrammatic side elevational view of an apparatus suitable for carrying out the invention. 7

Referring in detail to the drawing, 1 is a storage tank' which is connected'by means of a line 2in which is interposed a pump 3 and valve: 4, tothe'he'ating coil 5 mounted in a furnace 6, the'latter being heated by means of gas burner .7. The heating coil 5 is connected to a'vap'orizing chamber 6, which is in turn serially connected to suc ceeding chambers 7,8 and 9 by vapor pipes 10, 11 and 12 and liquid connections 13,14:

and 15 respectively. Thevapor lines 10, 11 and 12 are controlled by valves 16, Hand 18, While'the liquid lines 13, 14 and-15 are regulated by the valves 19, 20. and 21.1, Each of the chambers 6, 7 8 and 9 have residuum. draw-off lines 22'controlle'd by valves 23,

'which communicate with a single header 2 1- Which serves to return the residual products toLthe storagetankl. Each of the residuum lines has a secondary connection '25 con-- trolled by valves 26, by means of which the residual oil may be diverted from the residuum lines to separate storage-not shown.

Beneath the chambers 6 and 7 are provided burners 27,'by means of which the temperatures in the chambers 6 and 7 may be in-' creased "as desired.- From the top of the chamber 9 there is'a vapor line connection 28 controlled by Valve 29 to a refluxing or dephlegmating tower 3O. The dephlegmator in turn is connected by gooseneck 31, regulated by valve 32, to the'water condenser. 33, the discharge end of thecondenser coilbeing connected by means of a line 34, controlled by a valve 35, to the receiving tank 36, the

latter being equipped with a liquid draw-off valve 37 a pressure relief valve 38, a pressure gauge-39 and "a liquid level gauge 40.v

From the bottom of the dephlegmator a draw-01f line 41, in which is interposed a valve 412, communicates with a storage tank 1, by means of which the liquid reflux con- 7 densate separated from the vaporlin the dephlegmating zone'may be returned to the storage tank and recycled with the raw oil or charging stock to the heating coils to be retreated. V

In operation, the oil from the storage tank is charged by means of the pump 3 through the line 2 to the heating coil 5 and while circulating therethrough is raised to a conversion temperature. In this condition it is introduced to the initial chamber 6 of the battery of ,vaporzing chambers, where a portion of the volatile products will pass oil throu h' the line 10 to the succeeding chamber In a. like manner theliquid products, if the valve 19 be open, will 'Overflow into the chamber 7 and into the succeeding chambers in a similar manner. Thus ineach successive stage the oilwill have ample opportunity to become completely digested or assume an equilibrium whereby the -volatileproducts are separated from the higher boiling point liquid residual sub stances Wl1l0l1 are drawn off through the residuum lines 22 and returned through the header 24 to the storage tank.

stages of operation itis desirable to recycle substantially all of the residual products, as they are very'little carbon laden and do not add appreciable quantities of free carbon to the charging stock. As the process pro- .z."

ceeds and the residual oilsbecome heavier and containmore free carbon, it is advisable toby-pass the heavier products and recycle only the relatively carbon-tree oils. In order to produce this effect of diverting the In the initial heavier residual substances, the valve 19 is closed. Thus the heavier oils will collect in the initial and may be drawn oii through the line 25 tapped into the residual draw-off line 22 of the chamber 6. This will necessitate the valve 23 being closed and the valve 26 being open. In a similar manner, after the heavier oil has collected to a height so that it will overflow into the chamber 7, the valve 20 may be closed and the residual products isolated in the two tanks 6 and 7, and in a like manner the succceding tanks may be used to collect the heavier residual oils while only the lighter rellux and relatively light residual Sllb'i'fiilCQS recycled to the storage tank to be returned with the charging stock. It will be noted by operating the process in this manner that the apparatus may be run continuously for a much greater period of time, it be ing only necessary to keep the residuum lines from the chambers containing the heavier oils clear in order to divert the carbon laden products. Burners are supplied under the tanks 6 and 7 in order to add additional heat to the oil contained in these chambers, so as to promote the reaction taking place and increase the volume of vapors evolved from the oil in these initial stages. The size of the dephlegmator will necessarily have to be increased in order to supply sufficient dephlegmation to the vapors evolved in the various chambers. In place of the four tanks shown, additional tanks may be connected without departing from the scope of the invention. The features of recycling the unvaporized products from the conversion chambers and providing means for isolating and diverting the heavier substances and atthe same time recycling selected portions which are but lightly carbon laden, together with further advantages of continued operation over long periods of time and the accuracy of control which may be had over the apparatus, are "factors of importance in connection with the process. 1

By treating mid-continent oil of approximately 32 Baum gravity at temperatures ranging from 600 to 900 F. and passing them through vapor chambers serially connected as explained, I have been able to procure a substantial yield of high quality distillate having gravities of from 48 to 52 Baum and comprising from 40% to of the oil treated.

I claim as my invention:

1. A process for treating petroleum oil consisting in raising the oil to a conversion temperature in a cracking zone, passing the oil through successive vapor chambers in maintaining a superatmospheric pressure on the oil in said chambers, withdrawing the evolved vapors therefrom and subjecting them to a dephlegmating action, condensing the dephlegmated vapors and recycling the unvaporized oil from selected vapor chambers to the cracking zone for retreatment, and withdrawing the unvaporized oil from the remaining vapor chambers from the sys tem without returning the same to said cracking coil for further cracking.

2. A process for treating petroleum oil, consisting in passing a stream of oil through a cracking coil where said oil is subjected to a cracking temperature, in passing the highly heated oil through successively arranged vapor chambers, in causing the oil to accumulate in a pool in each chamber, in maintaining a superatmospheric pressure on the oil in each chamber, in applying heat to at least one of the first chambers of the series without applying heat to advanced chambers of the series, in subjecting the vapors to a reflux condensing action, in withdrawing a regulated quantity of unvaporized oil from a selected vapor chamber, and in recycling. said oil through said cracking coil for further cracking.

'3. A process for treating petroleum oil, consisting in passing astream of oil through a cracking coil where said oil is subjected to a cracking temperature, in passing the highly heated oil through successively arranged vapor chambers, in causing the oil to accumulate in a pool in each chamber, in maintaining a superatmospheric pressure on the oil in each chamber, in applying heat to at least one of the first chambers of the series without applying heat to advanced chambers of the series, in subjecting the vapors to a reflux condensing action, in withdrawing a regulated quantity of unvaporized oil from a selected vapor chamber, in mixing said oil with said reflux condensate, and in returning said mixed oil to said cracking coil for further cracking.

4:. A continuous process for cracking hydrocarbon oil, consisting in initially raising the oil to a cracking temperature, while flowing in a stream through a heating zone, in thence delivering the heated oil to the first of a series of reaction chambers through which the oil successively flows, in taking ofi? vaporous constituents from said reaction chambers for condensation and collection, in the early stages of the process removing from the first chamber of the series heavy unvaporized oil collecting therein, without again returning the same to said heating zone, while simultaneously returning the lighter unvaporized oil from the remaining chambers of the series to said heating zone for further treatment, and in a more advanced stage of the process removing the heavy unvaporized oil from a succeeding chamber of the series without returning the same to said heating zone.

5. A process for cracking hydrocarbon oil, consisting in circulating the oil in a cycle, in

one portion of which the oil passes in a restricted stream through a heating zone and is raised to a cracking temperature, and in another portion of which the oil successively flows through a series of reaction chambers, in initially circulating all of the unvaporized oil from said chambers through said heating zone, in thereafter, during the early stages of the process, removing heavy unvaporized oil collecting in the first chamber of the series from the"cycle,-While simultaneously recirculating the light unvaporized oil from the remaining chambers of the series, and in a more advanced stage of the process removing the heavy unvaporized oil from a succeeding reaction chamber of the series, and in continuously taking ofi vapors evolved from the oil in said reaction chambers for condensation and collection.

CARBON P. DUBBS. 

